Therrien said there is always a “gentleman’s agreement” between teams in a playoff series that coaches aren’t permitted to attend practices. When Samuelsson was spotted, Therrien said Samuelsson was told he wasn’t supposed to be there.

“There was no agreement between both teams,” Vigneault said Sunday. “That is the exception, not the rule. I’ve been asked in the past to do this on a couple of occasions. Usually the coach calls me or the GM calls the GM. It never happened.

“What happened yesterday was uncalled for. Without a doubt, my staff handled it with a lot of class just like our team plays whistle to whistle.

“It’s very regrettable. This is the National Hockey League. That type of behavior, we’re lucky it didn’t escalate.”

Therrien still believes both teams were on the same page.

“Myself and my coaching staff were all under the impression that there is a gentleman’s agreement, so probably there was a miscommunication,” Therrien said Sunday. “I don’t talk to coaches. This is a thing GMs talk about.”

This was just the latest in a series of escalating events that has taken this series to a level way above just the play on the ice. Montreal cut its deficit to 2-1 with an overtime win on Thursday before falling on Sunday in OT.

The Canadiens lost No. 1 goalie Carey Price for the rest of the series after Rangers forward Chris Kreider crashed into him while driving hard to the net. Things turned ugly in Game 3 when Montreal’s Brandon Prust hit forward Derek Stepan late, leaving the Rangers forward with a broken jaw that required surgery. Stepan was released from the hospital Sunday, and briefly stopped by Madison Square Garden to see teammates before returning home.

Prust was given a two-game suspension by the NHL.

Despite strong contention by some Canadiens that Stepan wasn’t hurt as badly as was suggested and would definitely be in the lineup for Game 4, he was ruled out by Vigneault on Sunday morning.

“No one wants to see a player get hurt,” Therrien said. “We don’t want to see Stepan get hurt. I’m sure they didn’t want to see Carey Price get hurt, but sometimes those things happen.”

Montreal forward Daniel Briere called Stepan’s injury “fishy.”

“It seems like a game,” he said Saturday.

That, too, rubbed Vigneault the wrong way.

“I can’t comment on their players saying Stepan’s injury is ‘fishy,'” Vigneault said. “We’re trying to play whistle to whistle. We’re trying to do the right things. I know in the hockey world we were painted as dishonest and dishonorable. We’re not. We follow the rules on the ice, we follow the rules off the ice.”

Derick Brassard returned to the Rangers lineup for Game 4 after being injured in the opener and sitting out two games. Therrien said Saturday that the Canadiens know what Brassard’s injury is, and suggested they could target him.

“There is no hockey player who is going to go on the ice, and no hockey coach is going to ask to hurt a player, but you have to play him hard,” Therrien said. “You have to play Derick Brassard, like we have to play all the New York Rangers: hard and with emotion. That’s playoff hockey. No one has a free pass.”

Vigneault cautioned Therrien that any further action could have serious consequences.

“I just hope that nothing happens to Brass,” he said, “because the player and Michel could be in trouble.”

Brassard filled in for Stepan, and J.T. Miller rejoined the lineup in place of suspended forward Daniel Carcillo, who received a 10-game ban for physical abuse of an official in Game 3.

Vigneault and Therrien have known each other for a long time and came up in the coaching ranks together. Therrien said Sunday that Vigneault is “a good friend and an important person in my life.”

But with a trip to the Stanley Cup finals on the line, both said any personal feelings must be put on hold during the heat of the playoffs.

“Right now we’re battling for the same thing,” Therrien said. “We’ve got to put our friendship aside for, what, two weeks? I’m sure when everything is done and everything is over, as soon as we get a chance to see each other, we’re going to have a nice cold beer, like we did in the past. Nothing is going to change.

“It doesn’t mean that I have no respect for him. I have tons of respect. He’s one of the reasons why the Rangers are here.”

Vigneault, replaced by Therrien as coach of the Canadiens during the 2000-01 season, used fewer words in describing their relationship.

“He said for this two-week period we’re not really friends,” Vigneault said. “He is probably right.”